Show HN: OnKey – I'm a bad singer, so I built an app to show where I'm off-key
Summary
OnKey is an open-source singing trainer for Mac that learns a song by listening to the music you play and then provides a live pitch display with per-line scoring. It leverages ML models such as CREPE, GAME, wav2vec 2.0, and MDX-Net Karaoke 2 for melody extraction and pitch detection, with a local-on-device processing pipeline that emphasizes privacy. The project includes build instructions, licensing (MIT), and contributor guidance, along with a live demo and usage notes.